Method and apparatus for treating metal articles



38 7 Sheets-Sadat l D'. c. TURNBULL Oct. 4, 1938;

METHOD AND APPARATUS FOR TREATING METAL ARTICLES Filed April 1, 19

Z am 1 7 a M 0 R M Y d 07W .5 m m M m 0 Q l E O fi wfl W m f m a, .M 5 w H m 0 a M- W m M J e 1 9 w n r T f 0 a a a, m w m 4 #W N 7 .l M 6 1 w w W W 0 I 6 a v flu A EEEEE 2 4 @6 4, D. c. TURNBULL 293319772 METHOD AND APPARATUS FOR TREATING METAL ARTICLES Filed April 1, 1938 7 Sheets-Sheet 2 9 INVENfQh I Jagfa 77071511]! ATTORNEY Oct. 4, 1938. D. c. TURNBULL 2,131,772

METHOD AND APPARATUS FOR TREATING METAL ARTICLES Filed April 1 1938 '7 Sheets-Sheet 3 Q vsww a INVENTOR BY W4 4% Q ATTORNEY Oct. 4, 1938. D, c TURNBULL 2,131,772

METHOD AND APPARATUS FOR TREATING METAL ARTICLES Filed April 1, 1938 7 Sheets-Sheet 4 ATTO RN EY Oct. 4,1938. D. c. TURNBULL 2,131,772

METHOD AND APPARATUS FOR TREATING METAL ARTICLES Filed April 1, 1938 7 Sheets-Sheet 5 Oct. 4, 1938. D, c TURNBULL 2,131,772

METHOD ANDAPPARATUS FOR TREATING METAL ARTICLES Filed April 1, 1938 7 Sheets-Sheet 6 5 w *1 v, M Q it a ATTORNEY 1938. D. c. TURNBULL METHOD AND APPARATUS FOR TREATING METAL ARTICLES Filed Aprill, 1938 7 Sheets-Sheet '7 INVENTOR ,J7ai 1i/ [3' 721111511 BY WMMQMZL ATTORNEY Patentecl- Oct. 4, 1938 UNITED STATES PATENT OFFICE IVIETHOD AND APPARATUS FOR TREATING METAL ARTICLES David G. Turnbull, Mishawaka, 1nd,, assignor to American Foundry Equipment Company, Mishawaka, Ind., a corporation of Delaware Application April 1, 1938, Serial No. 199,365

33 Claims.

In cleaning, polishing, hardening or otherwise treating the surfaces of metallic castings, forgings, and similar articles, it is desirable to turn or otherwise manipulate them through the abrasive stream in such a mannerthat all surfaces will be uniformly exposed and treated; ,It has heretoforebeen the practice to expose the sur- .face of the articles to the abrasive stream while the articles are turned or tumbled in a tumbling barrel or similar device. Tumbling barrels and cleaning mills heretofore known receive the articles therein in a batch, the barrel or mill is then put into operation, and when the articles have been sufficiently cleaned the barrel or mill is shut down to permit removal of the cleaned articles and the insertion of a fresh batch of uncleaned articles therein. In barrels and tumbling mills of conventional construction it often develops that certain of the articles remain on top of the batch with the result that certain articles are treated excessively while .otherarticles are not sufliciently cleaned or treated. The uncleaned or partly cleaned articles must then be'sortedout 0 from the cleaned articles, following which the partially cleaned articles must be returned to the mill for recle'anirlg. p v p According to the present invention various articles; such as castings, forgings, andirregular 5 metallic shapes, may be cleaned, pollshed,'hardened; or otherwise treated by a continuous proc-' Y ess.j The articles are deposited" on -'a suitable supporting surface whereon they 'are'tumbled.

about and while thus tumbled, are advanced 0 through a, stream of abrasive particles. The

process preferably is a continuous one, the articles being deposited on the supporting surface at 'onepoint and are carried through the abrasive stream and removed from the supporting 5 surface at another point, thus obviating the necessity for shutting down the apparatus except for purposes-of repair or adjustment. The

combined tumbling and forward movement of the articles also causes each article to be fully,

0 uniformly and thoroughly exposed to the abrasive stream for a sufficient time to effect coinplete and uniform treatment.

The invention also provides suitable apparatus forcarrying out this method which apparatus 5 preferably includes an abrasive projector of the conveyor.

centrifugal throwing wheel type having means to control the direction 'ofillght of'the abrasive. The articles to be cleaned'are carried through the abrasive stream by an endless flexible member suspended in such a way that the lower portion of the member defines a trough adapted to receive the articles to be treated. The endless member is caused to travel in such a way that the. articles are carried up one side Of'the trough and caused to. tumble back toward the bottom of the trough. The conveyor may be either mounted in inclined position or may be provided with associated means, such as lugs, to effect a forward movement of the articles along the Thus, articles may be disposed in the trough at the one end thereof and caused to travel along the trough and are discharged from the other end thereof. The trough is so positioned with respect to the abrasive projector that the articles pass through the stream in the course of the travel along the trough.

An object of this invention is to provide a method and apparatus whereby castings, forglugs and similar metallic articles may be continuously cleaned, polished, hardened, or otherwise treated.

Another object of this invention is to provide a method and apparatus for manipulating and tumbling articles being cleaned and treated so as to assure uniform treatmentof the same.

1 Still another object of this invention is to provide a method and apparatus for cleaning metal- 110 articles whereby the articles are given a combined advancing and tumbling movement through anabrasive stream having a generally fan-like pattern.

ficient in operation, relatively low in cost, and

which can be easily and quickly adjusted to handle articles of various shapes.

Various other features and advantages of the invention will be apparent. from the following illustrative description and from an inspection of the accompanying drawings.

Although the novel features which are believed to be characteristic of this invention will be particularly pointed out in the claims appended hereto, the invention itself, as to its objects and advantages, and the manner in which it may be carried out, may bebetter understood by referring to the following description takenin con-. nection with the accompanying drawings forming a part thereof, in which:

Fig. 1 is a horizontal cross-section view through one form of apparatus suitable for carrying out the present invention, this view being taken along line II of Fig. 2;

Fig, 2 is a longitudinal cross-sectional view of the apparatus taken on line 2-2 of Fig. 3;

Fig. 3 is a transverse vertical cross-sectional view of the apparatus taken on line 33 of Fig. 1;

Fig.4 is an enlarged fragmentary top plan view of a portion of the flexible conveyor belt, together with a portion of the cooperating driving roller;

Fig. 5 is a fragmentary cross-sectional view of the conveyor belt and driving roller taken along line 5-5 of Fig. 4;

Fig. 6 is a side elevational view of another form of apparatus suitable for carrying out the present invention, certain parts of the apparatus being shown in section to illustrate certaindetails of the construction;

Fig. 7 is a top plan view of the apparatus shown in Fig. 6, portions of the apparatus being shown in section to illustrate further details of the construction;

Fig. 8 is a transverse cross-sectional view of the apparatus,.this view being taken along line 88 of Fig. 6; i Fig. 9 is a rear elevational view of the apparatus;

Fig. 10 is a longitudinal cross-sectional view through still another form of apparatus constructed in accordance with the invention;

Fig. 11 is a transverse cross-sectional view of the apparatus taken along the line IIII of Fig. 10; I

Fig. 12 is an enlarged top plan view of a portion of the conveyor shown in Figs. 10 and 11; and

Fig, 13 is a side elevational view of a portion of the conveyor structure shown in Fig. 12.

In the following description and in the claims,

various details will be identified by specific names for convenience, but theyare intended to be as generic in their application as the art will permit. Like reference characters denote like parts in the several figures of the drawings.

In the drawings accompanying and forming part of this specification, certain specific disclosure of the invention is made for purposes of explanation, but it will be understoodthat the details may be modified in various respects without departure from the broad aspect of the invention.

In accordance with this invention, the apparatus as shown in Figs. 1 to 5 inclusive may comprise a. suitable supporting and housing structure I having a charging opening 2 in one wall and a discharge opening 3 in the opposite wall. Adjacent the charging opening 2 is a vestibule 43 which may be normally closed by flexible curtains 5. Extending from the charging opening 2 to the discharge opening 3 is a flexible conveyor;

prises a wheel II having a plurality of throwing blades I3 which may be mounted, if desired, between a pair of spaced side plates I2. The blades extend inwardly short of the center so as to define a central opening. Disposed in the circular opening is an impeller I4 which is preferably arranged to rotate with the blades I3 andwhich is surrounded by a tubular control member I5. The control member I5 is preferably adjustably mounted independently of the blades. The control member is provided with an opening I6 through which abrasive particles are thrown by the impeller into the path of the rotating throwing blades I3. By adjusting the clock dial position of the opening I6 the direction of flight of the thrown abrasive may be controlled.

The impeller I4, side plates I2 and throwing blades I3 are rotatably mounted on a shaft I60 which rotates in bearings II positioned on the top wall of the housing I. The shaft I60 may'be operatively connected to a suitable power source, such as a motor I8 which drives a pulley I9 operatively connected to a pulley 2| carried on the shaft I60 by means of a drive belt 20. The wheel II is supplied with particles of treating material by a. conduit 22 discharging into a hopper 23 which leads to and feeds into the impeller I4.

The treating material, sometimes referred to as abrasive, may be any one of a number of materials and may, for example,-consist of smooth particles such as steel shot or sharp abrasive particles such as cracked steel grits or clean, sharp, quartz sand, or other material suitable for cleaning, hardening, polishing or modifying the surl face of the work piece in the desired manner.

The wheel I I is driven by energizing the motor I8 which rotates the shaft I60 and causes the impeller I4 and throwing blades I3 to rotate. The abrasive fed to the .impeller is thrown through the opening IS in the control member I5 and deposited on the blades I3 and is carried along the leading faces of the blades I3 by centrifugal force and is thrown from the blades at or near the periphery of the wheel by combined centrifugal and rotary force. The abrasive spreads out into a fan-like stream a which forms an impingement pattern of elongated, generally rectangular shape extending generally in the plane of rotation of the wheel and having a width approximately equal to the width of the blades I 3.

Disposed below the flexible conveyor 8 is a floor 30 which may be shaped to form a hopper adapted to receive the abrasive which has been discharged from the wheel II. A screw conveyor 32 is disposed in the lowermost portion of the hopper and communicates with a transverse screw conveyor 33 which conveys the abrasive from the hopper 30, to an elevator 34 which elevates the abrasive to a suitable storage hopper (not shown) from whenceitgcan flow by theconduit 22 to the feeding hopper 23. A sprocket I 35, driven from a suitable source of power (not shown), may be provided to drive the screw conveyor 33 and the screw conveyor 32 may be suiter 49 and a stub shaft portion 59 journaled in -'the bearing 44. vInterposedv between the portions 42 and 59 is a knuckle joint 46 received in a recess 41 in the roller. The other end. of each shaft 4| is provided with a stub shaft 5| which extends. through an elongated opening 69 in the opposite end wall of the housing I and is journaledv in a pillow block 6| having a dovetail flange 62 slidable in a dovetail slot 63 formed in a track member 64 which may be supported on a bracket 65. One end of the central shaft portion 42 .may be provided with an enlarged socket 66, disposed in a. recess 61 in the roller 49 and formed with a shoulder 12 abutting the end wall of the recess 61. The socket 66 receives a stub shaft 5| which parts are slidably connected by a key 19. The stub shaft portion 5| is journaled in the bearing 6| and is connected to the main shaft 4| by a knuckle 1| Each pillow block 6| is provided with a threaded opening 89 which receives the threaded end 8| of a shaft 92. The shaft 82 is journaled in fixed bearings 83 and is provided with a hand crank 84. The threaded portions 8| are reversely threaded and thus rotation of the shaft actuates the pillow blocks 6| in opposite directions. The pillow blocks 6| may be brought closer together or separated by rotating the shaft 82 by means of the hand crank 84. The knuckles 46 and 1| permit considerable lateral movement of the shafts 4| and prevent them from binding in roller (as viewed in Fig. 2) to swing through a considerable are without withdrawing the stub shafts 59 and'5I from their bearings.

The roller 39 is also provided with a shaft 4| and associated adjustment mechanism similar to. the shaft and adjustment mechanism associated with the roller 49 and heretofore described, the details of which are not repeated in connection with the roller 39, shown in Fig. 1

The flexible conveyor 8 may comprise an endless belt99 of-sheet material of suitable strength and flexibility as, for example, hingedly connected metal slats, rubber, fabric, or other suitable material.

The belt 99 is trained around the rollers 39 and 49 and depends therefrom substantially in the form of a double U, and the upper carry 93 defines anupwardly concave trough 94 having side wall portions 95 and 96. The lower carry 91 when suspended is of generally similar shape to the upper carry 93 and approximately concentric therewith. Preferably,- the rollers 39 and 49 "are adjusted so that they are closer together ad- 'jacent the, discharge end of the housing than at the charging end. Thus, the sidewalls 95 and 96 of the trough 94 are closer together at the ,dischargeend and the bottom of the trough 94 is, lower than at the charging end. The trough thus slopes downwardly from the charging end to the discharge endof the housing, thereby to promote the movement of the articles longitudinally of the trough. It is understood, however,

tudinally extending grooves 92 in the rollers 39 and 49 when the belt 99 is suspended thereon, thereby providing driving engagement between the rollers and the belt 99.

The rollers 39 and 49 are driven from a motor I99 which may be mounted in a suitable position, as for example, on the top wall of the housing I. The motor I99 drives a sprocket |9| over which is trained a chain I92. The chain I92 is trained over' a sprocket I93 carried on the end of the stub shaft 59 in driving cooperation with the shaft 4| carrying the roller 39. Carried on the other end of the shaft 4| is a sprocket I94 and a similar sprocket I95 is carried on the corresponding end of the other shaft 4|. A driving chain I96 is trained over the sprockets I94 and I95 and around an idler sprocket I91. The idler sprocket is carried on a shaft I98 rotatable in a bearing I99 adjustably supported in a hanger 9 depending from the bracket 65. The idler sprocket I91 thus operates to adjust the tension on the chain I96.

Upon energization of the motor' I99 the roller 39 is driven, which in turn drives the sprocket I94 and chain I96 which drives the roller 49. Both of the rollers rotate in the same direction and thus the conveyor 8 iscaused to travel along an endless U-shaped path in the direction indicated by the arrows in Fig. 3. This movement 'causes articles which are supported in the trough 94 'to be elevated along the side wall 95 of the trough until they reach their angle of repose, whereuponthey tumble down -over the subsequently ascending articles toward the bottom of the trough and through the abrasive stream. n

discharge end simultaneously during tumbling movement.

Where a positive movement of the articles is desired, a plurality of lugs or other projections may be provided on the supporting surface. Re-

ferring to Figs. 4' and 5, each lug 5 may comprise a plurality of plates II6, each supported adjacent its outer end on a pin II1 carried in a bracket II8 suitably secured as by a rivet head II9 to the belt 99. The plates 6 may be'substantially in alignment, may overlap at their inner ends and may be connected by a pin 29 extending through slots I2I and I22, thereby to provide an articulated lug. v It will be seen that when the belt 99 is relatively planar, the lugs I I5 are straight and the plates II6 are in alignment.

However, when the belt passes around a roller (as, for example, roller 49) or is otherwise flexed, the plates II6 pivot about the joint pin I29, as shown-atthe right-hand'portion-of Fig. 5. Preferably, the lugs II5 are disposed in echelon arrangement on the belt 99 and are inclined and thus serve to advance the articles along the trough, thereby augmenting the forward movement of the articles produced by the inclination of the trough.

When the wheel II is rotated and supplied with abrasive, an abrasive stream a is projected which diverges fan-like from the wheel throughout a considerable angle and produces a generally elongated rectangular impingement pattern on a horizontal surface disposed under the wheel. Preferably, the height of the conveyor 8 is adjusted so that the marginal portions of the stream a strike the bottom of the trough 94 approximately at the ends of the conveyor 9. It is 1111-- charging end. The motor I is energized and drives the conveyor in the manner above described thereby to tumble the articles in the trough 94 through the abrasive stream and simultaneously advances them through the stream a. When the articles reach the end of the trough 94, they'drop off the conveyor 8 and slide along the chute 6 and out through the discharge opening 3.

The spent abrasive which is received in the trough 94 is also conveyed to the end of the conveyor and drops onto the chute, the opening 1 allowing it to drop into the hopper 30. If desired, theconveyor 8- also may be provided with slits or other openings (not shown) to permit the abrasive to pass into the hopper 30.

Preferably the rollers 39 and 40 are adjusted so that a substantial inclination of the trough 94 is provided and so that the side walls 95 and 96 are sufiiciently close together ,to confine the articles to a relatively narrow zone at the center of the housing. The. sidewalls 95 and 96 should be of such proximity and angularity that each article is effectively and completely exposed to the abrasive stream a. This can best be determined by experimentation with the various articles to be treated. Where the side walls are relatively steep and close together, the articles will be exposed to the stream for a relatively longer total 'period,' but will be arranged in greater depth or number of layers than where the sides diverge at a greater angle.

The conveyor belt 90 may be formed of various materials as, for example, rubber, fabric, jointed metal plates, interlocked chains or other perforate or imperforate materials of suitable strength and flexibility. A heavy rubber belt makes an excellent conveyor and it is not appreciably worn or damaged by the abrasive striking it while in motion. It is understood that the conveyor beltthe invention, the apparatus (see Figs. 6 to 9) comprises a suitable supporting and housing structure 2!, which preferably includes a frework 202, side walls 203, an inclined bottom wall 204 and a top wall 205. An opening 206 is provided in one wall of the housing and a loading vestibule 201 closed by flexible curtains 2ll8 cooperates therewith. A loading chute 209 extends from the charging opening 206 into the housing' for the purpose of depositing the articles to be treated on the conveyor, as will hereinafter appear. A discharge opening 2H is provided in the rear wall of the housing and is closed by a flexible curtain 2I2. A discharge chute 2l3 is disposed adjacent the discharge opening for conducting material to the conveyor out of the housing, andhas perforations 2 l4 for permitting spent abrasive to pass through the chute 2 l3.

Disposed in the lowermost portion of the housing 20l is a crew conveyor 2I5 communicating with a screw conveyor 2l6 for' returning spent abrasive from the housing to an elevator 2|! by means of which it is elevated to a suitable storage hopper (not shown).

Mounted on the top wall 205 of the housing is an abrasive projector B of the rotary, centrifugal throwing wheel type. Although various 'types of abrasive projectors may be employed, preferably the projector is of the general type comprising a wheel 220 having a plurality of throwing blades 222 extending from the central portion of the wheel towardthe periphery. -Means for feeding the abrasive into the path of the rotating blades 222 may include an impeller 223 preferably rotating with the blades 222. A relatively stationary control cage 224 is interposed between the impeller 223 and the inner ends of the blades 222 and is provided with one or more openings 22l through which the abrasive is thrown by the impeller 223 into the path of the blades 222.

The wheel 220 is mounted on a shraft 225.journaled in bearings 226 and is driven by a suitable source of power, for example, a motor 221. The motor may drive a pulley 228 fixed tomotor shaft 229 which is trained over a pulley 230 carried on the shaft 225. The motor may be suitably mounted on an extension 23l of the top wall of the housing and the wheel 220 may be enclosed in a casing 232 carried .on the top wall of the housing and may extend through an opening 233 in the top wall 205. A suitable abrasive is fed to the wheel from a hopper 234 which, in turn, may be fed from the storage hopper (not shown).

When the motor 221 is energized, it rotates the wheel 220 and abrasive fed to the impeller 223 is thrown into the path of the blades 222. The blades 222 project the abrasive downwardly into the housing 20l in the form of a relatively narrow stream 1) which may have-a substantially rectangular, elongated impingement pattern. The shape and direction of the stream b may be varied as desired by suitable design of the wheel and particularly of the control cage 224. Preferably the abrasive stream b is so controlled that it extends over a substantial portion of the interior of the housing as indicated in Fig. 6. One or more throwing wheels may be used, variously arranged as desired.

Suspended so as to hang within the housing in the form of a trough is a flexible endless conveyor member 240 which may comprise a flexible fabric or metal sheet, or a rubber belt. The conveyor 240 is suitably supported so that a portion within the housing 20I defines a trough having inclined side portions 24! and 242 and bottom portion 243.. The conveyor 240 extends through openings 244 and 245 in the side walls of 'the housing and flexible sealing members 246 and 241 are provided adjacent these openings for preventing escape of abrasive from the housing.

The conveyor 240 is suspended from a series is supported by a bar 251 connected by a pin of generally parallel rolls 250, 251 and 252 which preferably are arranged in two similar sets, one

265 and 266 by pins 261 and 268. The roll 25l' is supported in bearings 218 ans 2", the former being supported by a bar 212 connected to the lug 259 and a bar 213 connected to lug 262. The bearing 21! is supported in a similar manner by bars 214 and 215 connected to lugs 265 and 266, respectively.

The roll 252 is carried on a shaft 216 and is supported in bearings 211 and 218 in such a manner as to be self-aligning. The bearing 211 is carried by an integral extension 219 of the bar 213 and the bearing 218 is carried by a lever 288 pivoted-on the pin 268. The shaft216, is provided with a knuckle joint 28l whereby the shaft 216 can adjustitself relatively to the bearing 211. The other end of the shaft 216 is provided with an alongated recess 282 which receives a stud 283 which is keyed to the shaft by a key 284. The stud 283 has a knuckle joint 285 and thus the stud 283 is self-aligning with respect to the bearing'218. The knuckle joints 28! and 285 and the sliding connection between the stud 283 and shaft 216 permits movement of the bearing 218 with respect to the bearing 211 without binding of the shaft 216 in the bearings.

The lever 288 is integral with a sector 298 having gear teeth 29! meshing with a worm 292 carried on a shaft 293, journaled in bearings 294 on the rear side wall of the housing 28L A hand wheel 295 is provided for rotating the shaft 293. Whenthe hand wheel 295 is rotated, it effects rotation of both sectors 298 which, in turn, actuate their respective levers 288 and swing the bearings 216 inwardly or outwardly with respect to the housing 28L If, for example, the bearings 218 are swung inwardly, this causes the rear ends of the rolls 252 to be moved closer together and thus permit the conveyor 248 to narrow at this portion. This action causes the portion of the conveyor which is disposed in the housing 28| to be lower and the portions 24! and 242 to be inclined at a lesser angle from one another, thereby lowering the bottom portion of the conveyor 243. Since the bearings 211 are fixed bearings and the portions of the roll 252 at the forward end of the housing remain stationary, thus no" change is effected in the conveyor at this portion of the housing. The result of this movement, therefore, is to cause the rear end of the trough defined by the conveyor to be lowered with respect to the front end thereof.

Thus, by actuation of the hand wheel 295, the

386, driving a chain 381 which is trained overa sprocket 388 carried on the shaft 254. The shaft 254, 262 and 216 carry sprockets389, 3l8

and 3, respectively, and a driving-chain 312 is trained over all of these sprockets; Thus, upon rotation of the shaft 254, the driving chain is driven and rotates the remaining sprockets and their respective shafts, thereby rotating the several rollers.

I The operation of the apparatus is as follows: The motor 221 is energized to drive the projector 228 and abrasive material, is fed to the hopper 234, from whence it is fed to the wheel 228 and is projected thereby in the form of an abrasive stream b into the housing 2!". The projector 228 is disposed so that the abrasive stream 1) is projected against the articles p to be cleaned or treated supported upon the bottom portion 243 of the trough portion of the conveyor 248 and the I longitudinal axis of the impingement pattern defined by the stream b extends in the direction ofthe trough.

Articles 1) to be cleaned are introduced into the housing 28l through the charging opening 286 and are deposited from the charging chute 289 onto the trough portion of the conveyor 248. As indicated in Fig. 6, the charging chute 98 extends beyond the end of the conveyor 248 so that the articles will drop from the chute 289 onto the lower portion of the conveyor 248.

The motor 385 is energized and drives the conveyor 248 in the manner above described in the direction indicated by the arrow in Fig. 8. This causes the articles p to be carried up the side wall 242 of the trough and when the angle of repose is exceeded, the articles tumble down again toward the bottom 243 of the trough. As indicated in broken lines in Fig. 8, when articles are deposited on the conveyor 248, they cause a conveyor 248 to assume a somewhat different shape than when it is free of articles.

Owing to the inclination of the trough portion of the conveyor 248, the articles are advanced from the upper to the lower end thereof inthe course of which movement they are carried through the abrasive stream b. Although the abrasive stream b may extend over any desired portion of the length of the trough, preferably it extends over as large a portion-as possible in order that the articles 1) will be in the stream for the maximum time. When the articles p have advanced to the lower end of the trough, they drop from the conveyor 248 onto the discharge chute 2l3 from whence they slide through the discharge opening 2i i or may be removed by suitable apparatus. The spent abrasive passes through openings 2 M in the discharge chute H3.

The mechanism for adjusting the shape of the trough portion of the conveyor 248 not only permits the inclination to be varied as above described, but permits variation of the inclination of the sides and hence variation of the crossseotional shape to accommodate the conveyor more conveniently to articles of various shapes and sizes. Preferably the shape ofthe trough portion is so adjusted that the articles to be treated are confined to a relatively narrow zone within the housing and are tumbled into the abrasive stream a large number of times and retained therein throughout their entire period of travel through the housing.

The conveyor belt 248 may be formed from any suitable material such as rubber, fabric, metal plates carried on a chain, articulated flights, an

invention, the apparatus (see Figs. 10 to 13) in- 75 erably closed by one or more flexible curtains 408.

Suitably mounted on the top wall of the housing 40! are a plurality of abrasive projectors C and D adapted to project streams of abrasive c and d against the articles supported on the con-' veyor 405. Although two such projectors have been shown, any suitable number may be provided depending upon the size of the apparatus and other conditions. Preferably the projectors C and D are of the centrifugal throwing wheel type, which are provided with means for controlling the direction of flight of the thrown abrasive.

Each projector may comprise a wheel 4!0 having a plurality of spaced radially arranged, channel-shaped throwing blades 3- which extend from adjacent the periphery of the wheel 4! to a point inwardly short of the center, to define the central opening'4l4. Disposed in the circular space 4 is an impeller 4!!! having a plurality of vanes 4!9 which may be fixed to rotate with the blades 4!3 Surrounding the impeller M8 is a control member 420 having a discharge opening 42!. The control member is mounted independently of the blades 4! 3 and may be adjustable. By varying the clock-dial position of the opening 42!, the direction of flight of the abrasive may be controlled. Suitable means, such as side wall members 4| I and H2, may be provided to support the blades M3 in rotative position. Each through a feed pipe 424 extending through an opening 425 in the side plate 4! I and terminating adjacent the impeller M8. The abrasive may be contained in a suitable storage hopper, (not shown), preferably located above the wheel 4!0 so that the abrasive may flow to the wheel by gravity.

When the wheel M0 is rotated as described and abrasive is supplied thereto, the abrasive is hurled by the impeller 8 through the outlet opening 42! and into the path of the rotating throwing blades 4 !3. The abrasive is urged along the leading faces of the blades 3 and is hurled therefrom adjacent the periphery of the wheel by combined centrifugal and radial forces and an opening 421 in the wall of the housing 40! and suitable bafiles, such as the depending apron 428, may be provided for protecting various portions of the apparatus from the wearing effect of abrasive material. A hopper 430 may be disposed in the bottom portion of the housing 40! for receiving spent abrasive and a screw conveyor 43! may be disposed in the lower portion of the hopper 430 toconvey spent abrasive out of the housing 40!. A suitable elevator 432 may be provided for lifting abrasive to the storage hopper (not shown). Suitable driving means (not shown) may be provided for actuating the conveyor 43! and elevator 432.

The conveyor 405 preferably is formed from a plurality of individually rigid bars or aprons 450 extending between and carried by endless chains 440 and 44! suitably mounted adjacent the ends of the housing 40! respectively. Each chain may comprise a plurality of links 460 connected by link pins 46!, having guide heads 465. Each link preferably is formed with an opening 462 and a lateral extension 452 having a central slot 453.

The bars 450 preferably are formed by angle bars and are mounted in pairs on the extensions 452 with their flanges back to back and extending through the slot 453. Screws or other fastening members 45! may extend through the bars and extensions 452. The bars-45 0 attached to adjacent links 460 are sufiiciently spaced so that they will swing about the link pins 46!, thus imparting flexibility to the conveyor 405. Also,

the, spacing, of the bars 450 permits projected abrasive to pass through between the bars 450 and drop into the hopper430.

The chain 44! may be mounted on suitable sprockets 410, 41! and 412 carried on shafts 413, 414 and 415, respectively. Each end of each shaft is rotatably journaled in a bearing 416 supported on the housing wall. Preferably the shafts are disposed in generally triangular arrangement for imparting the generally arcuate shape to the chains 440 and 44! and the supporting bars 450 forming the conveyor. The chains 440 and 44! are guided along y the predetermined path by tracks 485 and 486 which may be carried on the opposite end walls of the housing 40! by mounting blocks 481 and 488, respectively. The tracks are so shaped, that the portion of the conveyor 405 between sprockets 412 and 413 defines an arcuate, barrel-like, supporting surface. The remaining portions of the tracks are suitably shaped to accommodate the remainder of the conveyor 405.

A head 411 may be mounted adjacent the charging end of the conveyor 405 and may comprise plates 418 and 419 defining a groove 480 at their peripheries. The head 411 may be mounted for rotation in a hub 40! journaled in bearing 482. The head 411 is freely rotatable and serves to provide a substantially vertical end wall for the charging end of the conveyor to retain articles in the trough. of the conveyor.

The conveyor 405 may be driven from a suitable source of power, such as the motor 480, which may be connected through a speed reduction mechanism 49! and a drive 492 to a sprocket 493 carried on the shaft 413. Upon energization of the motor 490 theshaft 413 is rotated, thereby rotating the sprockets 410 causing traveling movement of the conveyor 405. The conveyor heads 465 ride along in the tracks 485 and 486 and thus guide the conveyor 405 along a predetermined path, a portion of which is suspended in arcuate position, as will be seen from Fig. 11. The arcuate portion of the conveyor 405 constitutes .a-

' tumbled about by the movement of the surfaceso that they are completely exposed tothe action of the abrasive stream or streams. If desired, either of the sprockets 411 and 412 or both may be connected by suitable means (not shown) to the motor 490 and may exert a driving action on the conveyor 405.

The bars 450 may be provided with upstanding lugs 454 extending transversely and inclined to the bars 450. When the conveyor 405 is actuated, the lugs 454 engage the articles to be treated and advance them forwardly (to the left, as viewed in Fig. 10) simultaneously with their tumbling movement. However, if desired, the lugs 454 may be omitted and the conveyor 405 may be tilted downwardly toward the discharge end, in order to assist in advancing the articles therealong. In this case, theshafts 413, bearing 482, and tracks 485 and 486, are suitably inclined so as to position the conveyor in the desired inclined position. As indicated in the drawings, the conveyor 405 may,-if desired, be inclined and also may have lugs for advancing the articles. I

Thechute 401is disposed adjacent the ends of the bars 450 in a position to receive the articles tus may be omitted and a charging chute may be provided in a manner analogous to the discharge chute.

. The operation of the apparatus is as follows: The projectors C and D are actuated to project abrasive streams c and d into the housing 401, each stream having components extending throughout considerable ranges of angularity. Preferably, the projectors are so positioned that the streams c and d strike the articles supported on the arcuate supporting surface of the conveyor 405 approximately at its horizontal portion. Articles to be treated are supplied to the conveyor 405 through the inlet opening 402 at the charging end (right-hand end as viewed in Fig. 10). The articles are carried up the moving arcuate supporting surface provided by the conveyor 405 until they reach a height corresponding to their angle of repose, whereupon they tumble down over ascending articles and through the stream of abrasive. This tumbling movement of each individual article from the lower portion of the supporting surface to a higher level and back down again is repeated a sufficient number of times to thoroughly and uniformly clean the articles. Simultaneously with the tumbling movement the articles are advanced along on the conveyor 405. The streams c and d may be adjusted to impinge against any desired portion of the supporting surface but preferably they extend'over substantially the entire length of the housing. Thus, maximum efficiency of operation of the apparatus is attained. When the articles reach the end of the conveyor 405, they are forced onto the discharge chute 401 and slide out of the housing 401. I 7

From the foregoing, it will be seen that the 'present invention provides a method and apparatus whereby articles may be tumbled for, and uniformly exposed to, abrasive treatment in a substantially continuous operation without nenomical'to build and operate.

and thus a high eificiency of operation can be maintained.

The apparatus is relatively simple and is eco-' The parts which receive the most wear can be quickly and easily removed and repaired or replaced. The conveyor ,can be quickly and easily adjusted to produce the desired movement of articles of various sizes and shapes,and the belt automatically adjusts itself so that the articles are positioned directly under the abrasive projecting wheel and therefore are in the stream for the maximum length of time.

While certain novel features of the invention have been disclosed and are pointed out in the annexed claims, it will be understood that various omissions, substitutions and changes may be made bythose skilled in the art withoutdeparting from the spirit of the invention.

This application is a consolidation of my three copending applications as follows: Serial No. 88,290, filed July 1,1936 for Apparatus for treating articles; Serial No. 88,291, filed July 1, 1935 for Apparatus for abrasively treating metal articles, and Serial No. 88,293, filed July 1, 1936 for Method and apparatus for treating metal articles.

What is claimed is:-

1. Apparatus for abrasively treating metal articles including, an, abrasive throwing wheel for projecting a stream of abrasive particles, a flexible, continuous supporting element, means suspending said supporting element to provide an upwardly concave supporting surface, means for actuating said element to effect a tumbling movement of articles supported thereon, I and means associated with said supporting element for advancing said articles in a linear direction through said abrasive stream while tumbling on said surface.

2. Apparatus .for abrasively cleaning articles including, a housing, an abrasive-throwing wheel adapted to project a stream pf abrasive into said housing, a flexible endless conveyor belt, means mounting said belt whereby a portion thereof defines a concave .trough within said housing adapted to support the articles to be cleaned, means for efiecting a traveling movement of said belt for tumbling articles about thereon and through the stream of abrasive, and means for advancing said articles in a linear direction through said abrasive stream while being tumbled on said belt.

3. Apparatus for abrasively cleaning articles including, a supporting frame, an endless conveyor belt, means including a plurality of rolls mounted on said frame for suspending said belt to form a concave trough-likesupporting sur face, means for moving said belt to eiTecttufii-""' -bling of said articles on said supporting surface,

4. Apparatus for abrasively cleaning articles including, a supporting frame, an endless belt, means including a series of spaced rolls extendingin the same general direction for suspending said belt to form a concave trough-like surface, means for rotating said rolls to effect a traveling movement'of said belt for tumbling articles on said surface, an abrasive throwing wheel for projecting an abrasive stream against articles tumbled on said surface, and means for advancing said articles in a linear direction through said abrasive stream while tumbling on said surface..

5. Apparatus for treating articles including, an abrasive throwing wheel for projecting a stream of. abrasive particles, a flexible, endless conveyor element, means for suspending said conveyor element in double U-shaped form to define a trough-shaped supporting surface extending through the stream of particles, means for effecting traveling movement of said conveyor element thereby to tumble articles supported on said trough-shaped supporting surface, and means for advancing said articles in a linear direction through said abrasive stream while tumbling on said surface. I

6. Apparatus for treating articles including, means for projecting a stream of abrasive particles, an endless conveyor, means including a plurality of spaced rolls extending in the same general direction for suspending said conveyor in double U-shaped form whereby the upper carry defines a trough-shaped supporting surface extending through the stream of. particles, means for driving said rolls to effect a traveling movement of said conveyor so as to effect a tumbling movement of the articles through said abrasivev stream, and means for advancing said articles in a linear direction through said abrasive'stream while tumbling on said conveyor.

7. Apparatus for abrasively treating articles including, means for projecting a stream of abrasive particles, a flexible conveyor element extending into said stream, a plurality of spaced rolls for suspending said conveyor element to define a trough-shaped supporting surface, means for driving said rolls, and means on said conveyor element whereby traveling movement of said conveyor element advances the articles under treatment in a linear direction along said supporting surface.

8. Apparatus for abrasively treating articles including, means for projecting a stream of. abrasive material, a flexible conveyor belt defining a supporting surface extending into said stream, means supporting-said conveyor belt to define an article-supporting surface, means for effecting traveling movement of said conveyor belt to tumble articles supported thereon in said stream, and abutment means on said conveyor belt for positively moving said articles in a linear direction through said stream.

9. Apparatus for abrasively treating articles including, means for projecting a stream of abrasive material, a flexible conveyor belt defining a supporting surface extending into said stream, means supporting said conveyor belt to define an article-supporting surface, means for effecting traveling movement of said conveyorbelt to tumble articles supported thereon in said stream, and articulated lugs secured on said flexible conveyor belt for engaging and eifecting positive movement of said articlesin a linear direction through said stream.

10. Apparatus for abrasively treating articles I i including, means for projecting a stream of abrasive material, a flexible conveyor belt defining a supporting surface extending into said stream, means supporting said conveyor belt to define an article-supporting surface, means for effecting traveling movement of said conveyor belt to tumble articles supported thereon in said stream, and spaced lugssecured on said conveyor belt in echelon formation for positively effecting a tumbling movement and forward movement of said articles in a linear direction through said stream.

11. Apparatus for treating articles including, an endless belt, means supporting said belt in tubular loop form whereby a portion defines a supporting trough for articles to be treated, an abrasive throwing wheel for projecting a stream of abrasive material against articles in said trough, means mounting said wheel within said loop, and means for effecting traveling movement of said belt to tumble the articles therein and advance them through said stream, said abrasive throwing wheel being disposed substantially within the loop formed by said belt.

12. Apparatus for abrasively treating articles including, a support, a plurality of spaced rolls mounted on said support, a flexible conveyor belt suspended from said rolls to define a generally tubular loop having a concave trough portion adapted to receive articles to be treated, means for effecting traveling movement of said belt whereby to cause articles in said trough portion to be tumbled and advanced therealong, and an abrasive throwing wheel mounted on said support and positioned substantially within said loop for projecting a stream of abrasive against the articles in said trough portion. 4

13. Apparatus for abrasively treating articles including, a support, a flexible conveyor belt, a plurality of spaced and approximately parallel rolls mounted on said support inan arcuately disposed series and constituting means for supporting said belt in the shape of a non-reentrant, closed curve whereby the lowermost portion defines a flexible trough-shaped-portion adapted to receive articles to be treated, means for driving said rolls to effect the traveling movement of said belt thereby to tumble the articles'in said trough portion, said trough portion being inclined horizontally from end to end thereby to advance said articles along said trough portion simultaneously with said tumbling movement, and an abrasive throwing wheel for projecting a stream of abrasive particles against the articles on said belt.

14. Apparatus for abrasively treating articles including, a support, an endless flexible belt defining an article receiving trough, a plurality of. spaced and generally parallel rolls, means fixedly mounting certain of said rolls on said support, means mounting other of said rolls for adjustment relatively to said fixed rolls whereby to adjust the contour of said trough, and means for projecting a stream of abrasive particles against articles on said belt.

15. Apparatus for abrasively treating articles including, a support, an endless flexible belt, a plurality of spaced rolls extending in the same general direction and adapted to support said flexible belt to define a trough-shaped supporting surface, means mounting said rolls on said support, means for adjusting the inclination of the side wall-forming portions of said supporting surface which includes, a pivotally mounted member supporting at least one end of certain of said rolls, and means for adjusting the position of said pivoted member thereby to adjust the position of the roll carried. thereby relative to the remaining rolls and the contour of said trough, and means for projecting a stream of abrasive material against articles supported on said supporting surface.

16. Apparatus for abrasively cleaning articles including, a supporting frame, anendless conveyor belt, supporting elements mounted on said frame for suspending said belt in a single tubular loop sling to form a concave trough-like supporting surface, means for moving said belt to effect tumbling of the articles on said supporting surface, and an abrasive throwing wheel mounted on said frame within said loop sling adapted to project a stream of abrasive against articles on said surface.

17. Apparatus for abrasively cleaning articles including, asupporting frame, an endless belt, rollers mounted in said frame for suspending said belt in tubular form so that an interior portion thereof forms a concave through-like supporting surface, means for actuating said rollers to effect a traveling movement of said belt for tumbling articles-on saidsurface, and an abrasive throwing wheel positioned within said tube for projecting an abrasive stream against articles on said surface. v

18. Apparatus for abrasively treating articles including, a housing, an endless flexible element, means including a series of spaced rolls for suspending said element to define a trough-like supporting surface, means for variably adjusting the position of the terminal rolls of said series thereby to vary theheight and shape of said supporting surface, and means for projecting an abrasive stream against articles on said surface.

19.,Apparatus for abrasively cleaning articles including, a housing, an abrasive throwing Wheel adapted to project a stream of abrasive into said housing, a flexible endless conveyor belt, means on said housing for mounting said belt in a closed tubular loop passing around said wheel and positioning said belt whereby a portion thereof passes into said housing and defines a concave trough within said housing adapted to support the articles to be cleaned, openings in said housing to admit said belt, and means for effecting a traveling movement of said belt'for tumbling articles about thereon, and through the stream of abrasive.

20. Apparatus for blast cleaning metal articles including, a plurality of rigid elongated members, means connecting said rigid members together to form a flexible and substantially. continuous conveyor, means mounting said conveyor to define a trough-like supporting surface with said rigid members extending longitudinally of the trough, means for effecting a traveling movement of said conveyor to tumble articles supported in said trough transversely of the trough, means for advancing articles longitudinally along said trough, and means for projecting against articonveyor to tumble articles supported in said trough transversely of the trough, means including lugs upstanding from and extending transversely across said rigid members and inclined to the center line thereof for advancing articles longitudinally along said trough, and means for projecting against articles in said trough a fanlike stream of abrasive particles having an elongated impingement pattern extending longitudinally of said trough.

22. Apparatus for blast cleaning metal articles including, a plurality of relatively rigid surface- Wforming members, means connecting said mem- I bers in parallel relation to form an articulated,

endless, flexible and continuous conveyor, means mounting said conveyor to present an arcuate supporting surface forming a trough, a rotary centrifugal abrasive throwing wheel for projecting abrasive particles against articles on said supporting surface in a stream having an elongate impingement pattern extending in the same general direction as said rigid members, means for effecting a traveling movement of said conveyor element to tumble articles supported on said arcuate surface transversely of the trough, and means for advancing articles longitudinally along said supporting surface longitudinally of the trough and through said stream.

23. Apparatus for blast cleaning metal articles including, a rotary centrifugal abrasive throwing wheel having means associated therewith for controlling the direction of flight of the abrasive in a fan-like divergent stream having an elongate impingement pattern, a plurality of spaced flexible members, a plurality of rigid surface-forming bars extending between and connected to said flexible members in generally parallel relation to form a substantially continuous, endless, articulated, conveyor, guide means for each of said flexible members adapted to direct said conveyor to define a trough-shaped supporting surface extending in the same general direction as the impingement pattern of said wheel, means for driving said conveyor to effect tumbling of the articles supported on said troughshaped surface transversely of the trough, and means for advancing articles on said surface longitudinally of the trough and through said stream.

24. Apparatus for the continuous blast cleaning of metal articles including, a plurality of generally parallel rigid supporting members, means connecting said rigid members to form a.substantially continuous, flexible conveyor, means for supporting'said conveyor to define a supporting trough, at least one end of said trough being open to permit continuous discharge of articles therefrom, means for driving said conveyor to tumble the articles positioned in said trough transversely of the trough, means for forwardly advancing articles longitudinally in said trough, and means for projecting a divergent stream of abrasive particles against said articles in said trough, said stream having an elongated impingement path extending longitudinally of said trough.

25. Apparatus for blast cleaning metal articles including, means for projecting a divergent stream of abrasive particles, said stream having an elongate impingement pattern, a plurality of rigid elongated supporting bars, means connecting said bars to form a flexible conveyor, means mounting said conveyor to define a troughshaped supporting surface extending longitudinally of said impin ement pattern, means for driving said conveyor, and abutments upstanding from and rigid with said elongated bars and adapted to engage articles on said supporting surface for advancing said articles longitudinally of the trough.

26. Apparatus for blast cleaning metal articles including, means for projecting a divergent stream of abrasive particles having an elongated impingement pattern, a plurality of rigid elongated supporting bars, means connecting said bars to form a flexible conveyor, means mounting said conveyor to define a trough-shaped supporting surface extending in the general direction of said impingement pattern, means for driving said conveyor, and inclined lugs extending transversely of and rigidly upstanding from said elongated bars and adapted to engage articles on said supporting surface for advancing said articles forwardly along said surface.

27. Apparatus for blast cleaning metal articles including, a plurality of rigid surface-forming members, means connecting said members in generally parallel relation to define an endless flexible conveyor, means mounting said conveyor to define a generally trough-shaped supporting surface, means for effecting a traveling movement of said conveyor element to tumble the articles supported thereon transversely of the trough, means for advancing the articles longitudinally of the trough, a relatively stationary end wall disposed adjacent an end of said supporting surface, an article discharge means at the other end of said supporting surface for receiving articles from said surface, and means for projecting a divergent stream of abrasive particles against articles positioned on said supporting surface, said stream having an elongated,

impingement pattern extending in the direction of advancement of said articles.

28. Apparatus for blast cleaning metal articles including, a pair of endless chains formed by connected link elements, a plurality of rigid surfaceforming members extending between and connected to said links to form a substantially endless flexible conveyor, means mounting said conveyor to define a trough-shaped supporting surface for articles to be treated, means for driving said conveyor to advance articles on said supporting surface longitudinally of the trough along a serpentine path, an article discharge opening adjacent one end of said conveyor, and a rotary centrifugal throwing wheel for projecting a divergent stream of abrasive particles against articles positioned on said supporting surface, said stream having an elongate impingement pattern extending in the direction of advancement of said article.

29. Apparatus for blast cleaning metal articles including, a housing, a charging inlet in said housing, a discharge outlet in said housing, a

plurality of rigid, generally parallel surfaceforming members, means connecting said members to form a flexible endless conveyor, means mounting said conveyor element to define a trough-shaped supporting surface for articles to be treated, said supporting surface being inclined longitudinally of the trough to advance articles therealong from said inlet to said outlet, means for driving said conveyor element to tumble articles thereon, and means for projecting a fanlike stream of abrasive particles against articles positioned on said supporting surface, said stream having an elongate transverse cross-sectional shape extending in the direction of advancement of the articles from said inlet to said outlet.

30. The method of cleaning metallic articles which includes, imparting to the articles to be cleaned a combined tumbling and advancing movement along a generally linear path, and projecting a fan-shaped stream of abrasive having a generally elongated impingement pattern against the moving articles so that the longitudinal axis of said impingement pattern extends generally in the direction of advance of the articles under treatment.

31. The method of cleaning metallic articles which includes, delivering articles to a flexible trough-like supporting surface in substantially continuous feeding operation, effecting a traveling movement of said surface across said articles to be tumbled on said surface, establishing a fanshaped stream of abrasive particles having a generally elongated impingement pattern, and advancing the tumbling articles through said stream of abrasive in the general direction of the longitudinal axis of said impingement pattern.

32. The method of cleaning metallic articles which includes, tumbling the articles and simultaneously advancing them in a substantially linear direction through a fan-like abrasive stream having a generally elongated impingement pattern, the longitudinal axis of said impingement pattern extending in the general direction of linear movement of the articles tumbling transversely across said stream.

33. The method of blast cleaning metal articles which includes establishing a fan-like stream of abrasive particles, imparting a succession of upwardly directed impulses against articles to be cleaned to lift them above their angle of repose and thereby effect a tumbling movement thereof and simultaneously imparting a succession of forwardly directed impulses against said articles to advance them through said stream, said fan-like stream of abrasive particles defining an elongated impingement pattern so arranged that its longitudinal extent is substantially in the direction of the forward movement of the articles.

DAVID C. 'I'URNBULL. 

